<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=yes">
    <meta http-equiv="Content-type" content="text/html;charset=UTF-8">
    <title>Marker Clustering</title>
    <link rel="stylesheet" type="text/css" href="https://js.api.here.com/v3/3.1/mapsjs-ui.css" />
    <link rel="stylesheet" type="text/css" href="demo.css" />
    <link rel="stylesheet" type="text/css" href="styles.css" />
    <link rel="stylesheet" type="text/css" href="../template.css" />
    <script type="text/javascript" src='../test-credentials.js'></script>    
    <script type="text/javascript" src="https://js.api.here.com/v3/3.1/mapsjs-core.js"></script>
    <script type="text/javascript" src="https://js.api.here.com/v3/3.1/mapsjs-service.js"></script>
    <script type="text/javascript" src="https://js.api.here.com/v3/3.1/mapsjs-ui.js"></script>
    <script type="text/javascript" src="https://js.api.here.com/v3/3.1/mapsjs-mapevents.js"></script>
    <script type="text/javascript" src="https://js.api.here.com/v3/3.1/mapsjs-clustering.js"></script>
    <script type="text/javascript" src="./data/airports.js"></script>
  </head>
  <body id="markers-on-the-map">

    <div class="page-header">
        <h1>Marker Clustering</h1>
        <p>Cluster multiple markers together to better visualize the data</p>
    </div>
    <p>This example displays a map showing the distribution of 
        airports across the world. The locations were obtained by using 
        the <a href="http://openflights.org/data.html" target="_blank">OpenFlights Airport Database</a>. 
        Instead of adding a marker for each location, the data has been clustered, 
        and individual airports are only shown at higher zoom levels.</p>
    <div id="map"></div>
    <h3>Code</h3>
    <p>Marker clustering requires the presence of the <code>mapsjs-clustering</code> module of the API. 
      The <code>H.clustering.Provider</code> class is used to load in data points and prepare them for clustering. 
      The result is added to the map as an additional layer using the <code>map.addLayer()</code> method.</p>
    <script type="text/javascript" src='demo.js'></script>
  </body>
</html>
